Evaluation of Laser-Doppler-Fluxmetry for the diagnosis of microcirculatory disorders.

Background: The laser Doppler fluxmetry (LDF) is a non-invasive method to assess skin blood perfusion, measuring the flow of blood cells inside a tissue volume without harming the tissue. In the diagnosis of skin circulation disorders, the results of the LDF measurement are generally used in such a way that "normal" (or non-ill) or "pathological" values are achieved by comparison with a reference sample, for example of apparently healthy subjects.

Material And Methods: In this study, the values of LDF for the diagnosis of microcirculatory disorders in patients with coronary artery disease (n = 20) or in patients with microcirculatory disorders, already diagnosed by capillary microscopy (n = 46), were examined.

[Choosing wisely recommendations in angiology].

Background: The Choosing wisely initiative addresses measures of high medical impact which are frequently not appropriately performed according to expert opinion.

Objective: To increase the quality of indications by providing supportive information on diagnostic and therapeutic measures in the field of angiology.

Materials And Methods: As part of the Choosing wisely initiative, the German Society of Angiology has constructed five positive recommendations on underused measures and five negative recommendations concerning those possibly overused.

Effect of Ioxaglate on the cutaneous microcirculation in patients with coronary artery disease: Randomized, double blind, placebo-controlled study.

Radiographic contrast media (RCM) can initiate microcirculatory disorders. This study was performed to investigate effects of Ioxaglate on the cutaneous microcirculation. The investigation was carried out as prospective randomized double-blind comparison in parallel-group design on two groups of n = 10 patients each who had to undergo a diagnostic coronary angiography.

Tissue oxygen partial pressure in the tibialis anterior muscle in patients with claudication before, during and after a two-stage treadmill stress test.

Background: The role of the microcirculation in the pathophysiology and symptoms of peripheral arterial obliterative disease (PAOD) has been progressively emphasized during the past decades. Under resting conditions, already, the tissue oxygen partial pressure in the m. tibialis anterior (pO2im) is reduced to about 50% compared to healthy subjects.

Microcirculation in hypertensive patients.

Regardless of the mechanisms that initiate the increase in blood pressure, functional and structural changes in the systemic vasculature are the final result of long-standing hypertension. These changes can occur in the macro- but also in the microvasculature. The supply of the tissues with oxygen, nutrients, and metabolites occurs almost exclusively in the microcirculation (which comprises resistance arterioles, capillaries and venules), and an adequate perfusion via the microcirculatory network is essential for the integrity of tissue and organ function.

[Management of peripheral vascular disease based on current guidelines. Peripheral artery occlusive disease of the iliac and femoral arteries and carotid artery stenosis].

The article summarizes the recommendations of current European and American guidelines concerning the diagnosis and treatment of peripheral arterial occlusive disease and carotid artery stenosis. In comparison to older recommendations, current guidelines concerning endovascular treatment and concomitant medical therapy have been changed in recent years. With the exception of very complex and long lesions, endovascular methods are seen as the therapy of choice for revascularization of the iliac and femoral arteries.

Laser Doppler flux measurement for the assessment of cutaneous microcirculatio--critical remarks.

Back scattered Laser Doppler (LD) signals are composed of two different individual signals. The number of the moving particles and the speed of the particles in the measured tissue volume determine the frequency shift and the band width of the Doppler signal. The dependence of the Laser Doppler flux on the number of scattering particles is highly nonlinear: at very low hematocrit and high speed the axial migration of the cells to the centre of the blood vessels is very strong, so that in these cases - because of the parabolic flow profile - the Doppler flux measurement overestimates the mean real blood flow (up to two- or three-fold).

Correlation between postischemic vasodilation of the arteria brachialis and of the postischemic hyperemia in the adjacent microvascular bed.

Background: Endothelial cells secrete different mediators depending on biochemical and/or biophysical conditions, which can lead to vasodilation or vasoconstriction, respectively. Impaired endothelial responsiveness to specific vasodilator stimuli has been used as a surrogate marker of cardiovascular risk. Multiple methods allow testing endothelial responses in both microvessels and conduit arteries, but it is still unclear whether there is a relationship in endothelial function between these two different vascular beds.

Influence of rheological parameters on the velocity of erythrocytes passing nailfold capillaries in humans.

One thousand two hundred and fifty-six subjects (apparently healthy subjects and patients with cardiovascular diseases) were registered in a prospective study including demographical and clinical data, rheological parameters (hematocrit, plasma viscosity, erythrocyte aggregation, erythrocyte deformability) as well as the erythrocyte velocity in human nailfold capillaries under resting and postischemic conditions. A multivariate regression analysis showed that under resting conditions there was no correlation between rheological parameters and erythrocyte velocity in capillaries. The blood flow regulation seemed to be so effective, that pathological changes of the blood fluidity showed no effect on the velocity of an erythrocyte passing the capillaries.

[Exclusion of coronary artery disease using cardiac CT. What impact do CT results have on patient management?].

Rapid advancement of multidetector head computed tomography (MDCT) during the past 10 years has facilitated noninvasive evaluation of CAD (coronary artery disease). Since the introduction of 320-row technology, examination of the whole heart in a single heart beat with diagnostic quality has become feasible. Direct imaging of vessel morphology, a high sensitivity for CAD above 96%, and low requirements of patient compliance represent advantages over other imaging modalities, such as MRI (magnetic resonance imaging), scintigraphy, and echocardiography.

[Non-invasive diagnostics of chronic stable coronary artery disease: evidence-based and non-evidence-based diagnostic algorithms].

In Germany, every second left heart catheterization has no immediate interventional or surgical consequence. One main reason for this limited quality of indication of many left heart catheterizations is presumably the inaccuracy of preinvasive testing that is mainly based on clinical evaluation and exercise ECG in Germany. However, exercise electrocardiography has several limitations.

Reproducibility and reliability of the ankle-brachial index as assessed by vascular experts, family physicians and nurses.

The reliability of ankle-brachial index (ABI) measurements performed by different observer groups in primary care has not yet been determined. The aims of the study were to provide precise estimates for all effects influencing the variability of the ABI (patients' individual variability, intra- and inter-observer variability), with particular focus on the performance of different observer groups. Using a partially balanced incomplete block design, 144 unselected individuals aged > or = 65 years underwent double ABI measurements by one vascular surgeon or vascular physician, one family physician and one nurse with training in Doppler sonography.

[Structure and function of the peripheral venous system].

The peripheral venous system is subdivided into a superficial (epifascial) and a deep (subfascial) system by the superficial fascia. The two systems are interconnected by the transfascial system, called perforanting veins. The blood from the superficial system (great saphenous vein and small saphenous vein) is drained to the deep system.

[Secondary prophylaxis of venous thromboembolism].

Making decisions about any modality of secondary prophylaxis in patients with venous thromobembolism (VTE) has to balance the risk of bleeding induced by anticoagulants against the benefit of reducing the risk of recurrent disease. It has to be kept in mind that the magnitude of risk is not only defined by the number of events per time period but also by the impact of the event on the fate of the patient. With standard intensity vitamin K antagonists (VKA), the risk of bleeding is more closely related to comorbidities than to other factors, eg age.

[Risk adapted therapy in vascular diseases: antihypertensive treatment in peripheral arterial disease].

Arterial hypertension must also be consistently treated in patients with PAD. Current guidelines and recommendations have to be considered, although in some patients the walk performance may be affected temporary by blood pressure dropping. In PAD, ideal antihypertensives are ACE inhibitors, AT1 receptor antagonists, calcium channel blockers and also alpha receptor blockers in combination.

Effect of LDL apheresis on oxygen tension in skeletal muscle in patients with cardiac allograft vasculopathy and severe lipid disorder.

In this study, the extent to which intramuscular pO2 is influenced by a single HELP-apheresis (Heparin-induced Extracorporeal LDL Precipitation) was investigated in 10 patients with cardiac allograft vasculopathy (CAV) and severe lipid disorder. For this purpose, a sterile flexible pO2 microcatheter was inserted into the anterior tibial muscle and pO2 monitoring was begun 10 minutes before starting apheresis treatment. The intramuscular pO2 values were recorded continuously until the end of apheresis treatment and a subsequent 30-minute further observation phase.

Effect of naftidrofuryl on intramuscular partial oxygen pressure (pO2) prior to, during and after physical load on the treadmill in apparently healthy subjects.

Previous studies demonstrated that naftidrofuryl increased the cutaneous and intramuscular tissue pO2 at rest. The presented open prospective pilot study is to investigate in apparently healthy subjects (n=12) whether naftidrofuryl also affects pO2 in situations of muscular stress. The pO2 is measured with a flexible probe in the anterior tibial muscle during treadmill exercise prior to and after one-week treatment with 100 mg of naftidrofuryl administered three times a day.

Influence of Iodixanol-270 and Iopentol-150 on the microcirculation in man: influence of viscosity on capillary perfusion.

Unlabelled: PURPOSE, MATERIAL AND METHODS: The aim of this study was to investigate the influence of direct intraarterial application of the contrast agents Iodixanol-270 and Iopentol-150 on the capillary perfusion. This was accomplished through continuous recording of the capillary perfusion in the nailfold capillaries of the right hand before and after a bolus injection of 20 ml of contrast agent into the right axillary artery.

Results: After injecting 20 ml of Iodixanol-270, which has a high viscosity compared to the plasma viscosity, a statistically significant decrease in the erythrocyte velocity of 60.

Influence of radiographic contrast media (Iomeprol 350 versus Iopentol 350) on cutaneous microcirculation: single-center prospective randomized double-blind phase iv study in parallel-group design.

Objective: This single-center, prospective, randomized, double-blind phase IV study in parallel-group design was carried out to investigate whether either of two different x-ray contrast media (iomeprol 350 or iopentol 350) injected into the axillary artery has any influence on cutaneous microcirculation.

Methods And Results: The investigation was carried out on two groups of patients (n = 10 in each group) who had to undergo a diagnostic heart catheter angiography. The confirmatory response variable for the study was the mean capillary erythrocyte velocity (mm/sec).

Intramuscular oxygen partial pressure in the healthy during exercise.

The oxygen partial pressure (pO2) in the anterior tibial muscle was measured in n=12 (6 physically active and 6 sedentary) apparently healthy subjects. This was the first time a flexible micro catheter with an outer diameter of 0.45 mm was used during skeletal muscular activity in men.

[Incomplete thrombosis of the inferior vena cava, a cause of chronic recurrent lung embolism. Diagnostic possibilities and case report].

Detection of complete inferior vena cava thrombosis is relatively simple because of the clinical symptoms and the pathological results of cw Doppler sonography in the region of the common femoral vein. Drainage volume detectable by means of venous occlusion plethysmography is considerably reduced during the acute phase, but normalizes with increasing degree of collateralization. In case of incomplete inferior vena cava thrombosis clinical signs, cw.

[Blood fluidity in essential hypertension, arterial occlusive disease and diabetic angiopathies].

Microcirculatory disturbances are important complications in hypertension, arterial occlusive disease (PAVK) and diabetic angiopathies. The special haemorrheological diagnostics for the judgment of the terminal vascular bed tended to the comprehension of the haemorheological risk. Due to the increase of the aggregation of erythrocytes and viscosity of the plasma in peripheral arterial occlusive disease and diabetic angiopathies this risk proved to be distinctly increased, in diabetes mellitus without vascular complications and essential arterial hypertension it proved less distinctly increased.

[Venous capacity and drainage volumes of arm veins].

On 29 test persons after clinical angiological and cw-Doppler-sonographic exclusion of an obstruction of the deep veins and an arterial occlusive disease on the upper extremities the capacity of the veins and the drainage volume were determined by means of the venous-occlusion plethysmography. The angiological measuring places Compactus 540 and Periquant 3800, respectively, of the firm Gutmann (group 1) and the 2-channel occlusion plethysmography of the former nationally owned measuring device factory Ballenstedt (VEB Messgerätewerk Ballenstedt) (group 2) were at our disposal. Apart from the obsolute values of the capacity of the veins and of drainage volume on account of the large interindividual dispersions the quotients were determined in the comparison of sides.